i am sure that Robert krinkland is Red John and i become sure of that in tha last episode ( ep 16 in season 5 )
my Prove :
first robert laughs when patrick is about to see


Lorelei Martins

has been killed by red john you can see it again and assure
he banned patrick to ride the ambulance and caught him
his relation to betram to become sure he is out of any suspicious ?
second the director make him shakes hand with patrick obviously and no reasonable cause for shaking meaning ( not in a meating or introduction ,robert wants to shake hands with him especially ?????? )
  robert has a shot in a car Limousine just like luther being killed and Lorelei Martins was caught
third  his voice is very suspicious and look same in tha last episode in season 2 ???????? make a comparison and you can see the similarities

                           thanks , 
                            
 

Okay, first of all, there are many elements that the producers seems to put forward to make sure that the public will notice so I'm guessing that these people are people of interest but not Red John himself.
First of all, Agent Ray Haffner is suspicious when he leaves the room when Teresa Lisbon asks him if he worked on the farm where Red John first drew the smiley face. He has shaken Jane's hand however, he wasn't at all smart enough to stop Jane's plan to reinstate his old team in the early season 4.
Then, there is Bob Kirkland. In my opinion, he is a person to look out for, although many people are saying that Lorelei Martins was behind bars when they shook hands and that there was no way for her to know they've shaken hands, there are always ways for people to know things in prison, especially if you are connected to Red John. He was the one who asked Alexa Schultz to ask Minelli to keep the FBI in the loop for updates on the Red John case now that Jane joined the CBI and Red John knows that Jane is a very smart man who could make a break in the case.
In the Bosco murder case, at the end, Rebecca told Jane that Red John had Bosco's team murdered because he knew Jane wanted the case back, so maybe Judge Manchester is somehow involved because he probably knew that Jane was going to pull some kind of trick to annoy the FBI and don't forget the "He is Mar" written on the wall where the "r" could well be an unfinished n. 
Maybe Red John might also have a link to Jane's past considering the whereabouts of Lorelei Martins' body and our knowledge of Jane's past.
Anyways, just thought I might explain a bit of what I think

Red John is male, and not PJ.

Fact: In the last episode, the guy being tortured refers to Red John as "HE" for several times. 

Fact: He and Lorelei does not call Patrick Jane as Red John.

So, we can throw all theories about RJ being a famale character to garbage.

I think Danny is Red John - he's been top suspect among others.

1. Danny had an act on the carnival, just like Jane before becoming a con-man. Cho confirms this Cackle, Bladder, Blood - Is this how Red John came about?

2. Where Lorelei was killed it had things you would have a carnival if you watch that scene again you'll see a rocking horse and those games where you have the hammer and whack it to score points.

3. Ruskin means "red hair one" 

4. Danny means "God is my judge"

5. As for the smiley face this may come from the carnival 

6. There was also, a caravan where Lorelei was killed, when Jane revisited the carnival there were caravans - Is Lorelei murder scene a huge clue?

7. Danny was angry at Jane for taking his sister away - was killing his family an act of revenge?

8. Considering Danny was family they weren't close - due to him being angry.

9. If Danny is Red John, what caused him to kill people before Charlotte and his sister?

10. Red John liked the blind girl to play the piano, shown in a flash back Charlotte was a gifted in this from a young age.

11. I don't think they are both dead - I think Charlotte is still alive - because when Jane drank that tea he only saw Charlotte and not both of them. 

12. There are no date of birth or death on there grave stones - Patrick would know why surely or a least question it? Danny asks him this: "Why haven't you been here since the funeral?"

Patrick: replies "Because they're not here."

Thoughts?             

I accuse Patrick Jane's wife, Angela Ruskin Jane, as being Red John.  I believe she is still alive.  I will try and list my points in bullet format for simplicity.
1. There are no dates on the tombstones for Jane's wife and daughter.
2. When Jane visits the graves with his brother-in-law (Danny) in "Cackle-Bladder Blood" he says it is the first time he has been there since the funeral because "they are not really there."
3. Also when talking with Danny earlier in the episode he says about his wife "that was our thing, that's what we did, we escaped together."
4. Jane is a name that can be male or female, however the more common association is female.
5. An alternate name for "Patrick" is "Pink" and an alternate name fore "Jane" is "John" which together means "Pink John."
6. The name of Patrick's wife is Angela Ruskin Jane (Ruskin is the maiden name).  The meaning of the name "Ruskin" is "red haired."  Put the two together and you have "Red Haired John" or, "Red John."
7. This would explain the uncanny, almost obsessive relationship Red John and Patrick Jane have with each other.

Keep in mind both Patrick and Angela were "carnies" together and she must have been incredibly intelligent as well, how else could she win Patrick's heart.  And faking death's is something we've seen a few times throughout the series. And Red John being a woman could explain Red John's 'way with women.'

Thoughts?

i think RJ can't be Jane, he must be someone who knew Jane before he first started murdering people; my argument is a little clumsy : the RJ smiley looks quite like Jane's face especially the eyes, i believe RJ is someone who's obsessed with Jane and who's killed his family not because Jane mocked him but because of his obsession with him, it's not all, remember what Lorelei asked jane to bring as a present to be his friend : Lisbon's dead body; if RJ really wanted to see Jane's change of heart he could ask anyone's dead body from Jane,the Jane who can't kill a fly, but no, he was more meticulous, he asked for the body of someone Jane cherishes the most, but who would know the person Jane cherishes the most (except Jisbon's fans and Bosco), if he is not someone obsessed with JAne, probably a woman, remember the case where the victims wrote at the wall "he is a man", i don't think it was the victim's writing.

i think some suspects, especially those who were murdered, should be removed from the list: Craig, Dr steiner, Wainwright, bosco and Lorelei; at the mean time i don't have tangible evidence to accuse any one of them but i suspect brenda shettrick and Oscar Ardiles to work for RJ.  
i have a question, why Wainwright was murdered by RJ? was he an accomplice? 

Two things we can take from the latest series is that it is likely that rj is working with homeland. Possibly training assassins. Didn't Lorelei seem a little too professional to be an amateur? And those who claimed rj is pj are know definitely wrong as Lorelei would have killed him.